CVE-2026-93739 in A3002MU
Summary
by MITRE • 09/18/2026
A vulnerability was determined in Totolink A3002MU Hh-B20211125.1046. This impacts the function formWlAc of the file /boafrm/formWlAc. Executing a manipulation of the argument submit-url can lead to buffer overflow. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in Totolink A3002MU firmware version Hh-B20211125.1046 represents a critical security flaw within the device's web management interface, specifically targeting the formWlAc function located in the /boafrm/formWlAc file. This component is responsible for processing administrative configuration requests submitted through the router’s web portal. The core technical issue stems from an improper handling of user-supplied input, particularly when manipulating the submit-url argument. During execution, the application fails to adequately validate or bound-check the length and content of this parameter before copying it into a fixed-size buffer in memory. This lack of rigorous boundary checking creates a classic buffer overflow condition where excessive data overwrites adjacent memory locations, potentially corrupting the stack or heap structures essential for normal program operation.
From an operational perspective, this vulnerability allows for remote code execution without requiring authentication if the web interface is exposed to untrusted networks, although many such devices may require initial access depending on their specific configuration and network placement. The ability to execute arbitrary commands remotely makes this a high-severity issue that can lead to complete compromise of the affected device. Attackers leveraging this flaw could inject malicious payloads into the router’s memory space, gaining control over the underlying operating system. This level of access enables adversaries to pivot within internal networks, intercept sensitive traffic, install persistent backdoors, or use the compromised device as a node in botnets for distributed denial-of-service attacks. The fact that an exploit has been publicly disclosed significantly lowers the barrier to entry for malicious actors, increasing the likelihood of automated scanning and exploitation campaigns targeting this specific firmware version across global deployments.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifiers such as CWE-120 Buffer Copy without Checking Size of Input and potentially CWE-78 Improper Neutralization of Special Elements used in an OS Command if the overflow leads to command injection capabilities. In terms of tactical classification under the MITRE ATT&CK framework, this flaw facilitates Initial Access through exploitation of a remote application vulnerability (T1190) and may enable Privilege Escalation or Defense Evasion depending on how the payload is executed within the constrained environment of an embedded device. The persistence of such vulnerabilities in consumer-grade networking hardware highlights ongoing challenges in secure coding practices for IoT devices, where resource constraints often lead to simplified input validation mechanisms that are easily bypassed by determined attackers.
Mitigation strategies must prioritize immediate firmware updates provided by Totolink if available for this specific build. Administrators should verify the installed version against vendor advisories and apply patches as soon as they become official releases. In cases where patching is not immediately feasible, network-level controls such as firewall rules restricting access to the web management interface from untrusted networks can reduce exposure. Additionally, disabling remote administration features entirely if they are not required for legitimate use cases significantly diminishes the attack surface. Security teams should also monitor network traffic for anomalous patterns indicative of exploitation attempts against known vulnerable firmware versions and ensure that intrusion detection systems are updated with signatures targeting this specific buffer overflow exploit chain to detect and block active attacks in real time.